Pumping apparatus



July 3, 1945. J. MERCIER 2,379,539

PUMPING APPARATUS Q I Filed April 1, 1942 2 Sheets-Sheet 2 ,Zbven'l'oz: JEAN MERC/ER n6. t'grney Patented July 3, 1945 2,379,539 7 v PYUMPINGAPPAVRATUSY- I Jean MercierQNew York, N. Y.

. t Application April 1, 1942, Serial No. 437,123 j I In France April 3, 1944, I,

The present invention relates to apparatus for pumping-liquids and more especially forjdeep pump n v t It is concerned with pumps of the type in which the c olumn. of liquid in-thepump main is yieldingly supported and caused to perform oscillations, This type of pump is usually soarranged that the final phase of the upward movement of the column produces a suction efiect whereby a supply of liquid is drawn-generally through a non-return valve-into the base portion of the pump main while a corresponding quantity of liquid isdirectly or indirectlydischarged from the pump. v

.A primer mover, generally a piston-cylinder unit, supplies the required energy by imparting an inpulse to the liquid column at th beginning of the downward movement and of such force that the energy accumulated inthe yieldingsupportat the end of the downward. movement is sufficient' to produce the desired upwardmovement.

r I have found that the energy efficiency of pumps of that type depends to a great extent upon the correct timing of the impulses imparted to the liquid column by the primary mover. This applies, particularly, to machine actuated pumps.

It is an object of the present invention automaticallyto synchronize the action of the primary mover with the given period of oscillation of the liquid column so that the mover acts'on the column during the downward movement without interfering with its rise. I v

To that end I provide pilot means controlled by the flow of fluid in the pumping apparatus which are adapted to govern the operation of the machine actuating the same. It is a feature of the present invention thatthe aforesaid pilot means .afiord efiective synchronization even in case of variations of the period of oscillation of the liquid column.

According to a further feature of my present invention additional masses maybe incorporated.

in the oscillating system to reduce the frequency of the oscillations. This featur is of advantage in connection with manually operated pumps whenever the given period of oscillation requires an inconvenient rhythm of power strokes. It may also be applied to machine operated pumps where it will afford a possibility to reduce the output of a given pump without materially affecting the energy efiiciency. 7

Other features of the present invention will result from the following detailed description 10f three embodiments thereof, given by way, of exbodiment in which the ample and illustrated in-the accompanying draw- Fig. l isa diagrammatical section of an apparatus for pumping water from a well according to the present-invention;

Fig. 215 apartial diagrammatical section showing a'modification of the'embodimentof Fig. 1-;

' non-returnvalve l0 whichcontrols the admission of liquid into pipefi. I

I e A piston 2 slidably engaging pump body! is provided to impartimpulses, tothe liquid column in p fi-i :1

Piston 2- is; actuated by an electric motor 4, driving, through a beltand apulley, a toothed wheel 5 in mesh with araclgll rigid with the piston rod-3, Suitable means a (not shown.) cause wheel 5 to engagera'ck- II when motor! is working and to disengage the same when the latter is stopped. The electric circuit: l2- of the motor 4 includes a contact 1-3-44 for closing or interrupting this CilGLll'ta- Contact 13 maybe-stationary, while contact 14 is carried by a leverlB pivoted at ISA. This lever 15'- i c0nnected,.at

15B andl5C, to the rods Qrtwo small pistons lfi and H slidable i-n cylindrical tubes connectedthrough conduits l8 and" i9 with the interior of pipe ii containing the column of liquid. Conduit it opens into pipe Bthrough a branch extending upwardly, while conduit 13 opens into the same pipe; 6,; but through a branch extending downwardly I I Pistons 'I t and H float. on the liquid in conduits I8 and t8 and prevent outflow of liquid from the same} Contact I l and lever l5 are so arranged that the former engages contacti3 whenever the level of the liquid in' conduit I08 e sfi bove that of the When piston 2 has completed a forward stroke spring 9 is fully compressed and movement of the liquid column momentarily ceases. Consequentl the liquid levels in conduits I8 and I9 become equal, contacts I3 and I4 are separated from each other and motor 4 is stopped.

When the column of liquid which oscillates in pipe 6 starts rising under the eflect of the expansion of spring 9, it exerts pressure upon the liquid contained in conduit I9, which rises and lifts piston I'I. Lever I5 pivots upwardly and moves contact I4 away from contact l3 whereby circuit I2 of motor 4 is kept interrupted. Piston 2 is pushed back into its extreme right hand position and liquid is discharged through the upper opening in pump body I. The rise of the liquid column continues due to the inertia of the liquid body after spring 9 isfully expanded. During this final phase of the upward oscillation the pressure in the bottom portion of pipe 6 and in casing I drops below that of the liquid surrounding the same, slide valve III is lifted and liquid admitted. When the column of liquid starts moving downwardly check valve I is closed. The liquid present in conduit I8 rises, pushes piston I6 upwardly and lowers lever I so that contacts I4 and I3 meet. Circuit I2 is thus closed, motor 4 starts and pushes piston 2 toward the left. The movement of motor 4 is stopped by the outward displacement of piston II.

In the embodiment of Fig. 21, the impulses intended to sustain the oscillations of the column of liquid are supplied by an elecro-magnet 20-2 I The circuit I2 of the coil of the electro-magnet includes, as in the preceding embodiment, a contact l3--I4 controlled by a lever I5 subjected to the action of pistons I6 and I I.

The operation is analogous to that which has been above described. The closing of contacts I3I4 energizes the electro-magnet, whose core 20 is then pulled downwardly and acts directly upon piston rod 3. The upward movement of the column of liquid causes contact I3I4 to be interrupted, de-energies the electro-magnet and allows piston 2 to move upwardly under the effect of the liquid thrust.

In the arrangement shown by Fig. 2, the liquid flowing out from the pump body I passes through a reservoir 22, containing at its upper part, at 23, a compressed air cushion, and acting as an accumulator, so that the liquid delivered by the pumping apparatus through pipe 24 may have a continuous flow. The period of oscillation of the column of liquid depends obviously from the length of this column which may lead, in some cases, to the necessity of movements at a rhythm which is inconvenient. In this case, according to a feature of the invention, I introduce into the oscillating system an additional mass which modifies the period of oscillation of the whole. This additional mass may be mounted in any portion of the oscillating system, that is to say either on the elastic suspension means or on the device for sustaining the oscillations of the whole, or again in the column of liquid itself.

In the embodiment of Fig. 2 electro-magnet 20 carries additional masses M to correct the period of oscillation of the liquid column.

In Fig. 3, the motor which supplies the desired impulses to the column of liquid is actuated by a fluid under pressure, including for instance a piston 25 rigidly connected to piston 2 and sliding in a, cylinder 26 adapted to be connected alternately with an inlet opening 21 for fluid under pressure and with an outlet opening 28 for the same, these openings being controlled by a slide valve 29.

This slide valve 29 is operated in response to the oscillations of the column of liquid in pipe Ii in the following manner:

Pipe 6 is connected to the pump body I through a chamber 30 communicating with pump body I through a passage 3| adapted to accommodate exactly a piston 32. This piston 32 i subjected to the elastic action of a spring 33, which tends to push it toward the right. It is carried by a rod 34 connected to a lever 35, pivoted at 36, which lever is, in turn, connected by a link 3'! to slide valve 2 9.

The oscillations of the liquid column are possible by an arrangement of the lower portion of the pumping apparatus similar to that in the preceding embodiments.

During the principal phase of the upward movement of the liquid column piston 3 is in its extreme right hand position so as not to interfere with the communication between delivery pipe 6 and pump body I. At the same time piston 32 projects beyond passage 3| into the interior of body I. In this position of the piston 32 slide valve 29 obstructs inlet 21 while cylinder 26 is in communication with outlet 28. The beginning of the downward movement of the liquid column carries piston 32 into the position shown whereby slide valve 29 closes outlet 28 and opens inlet 21. Accordingly, fluid under pressure enters cylinder 26, driving pistons 25 and 2 to the left into the position shown. This amplifies-the downward movement of the liquid column which forces sliding member 8 downward in casing 'I and compresses spring 9. When the column of liquid rises in pipe 6, piston 32, under the combined actions of this liquid end of spring 33, moves past passage 3| and penetrates into the pump body I. Accordingly lever 35 and link 31 displace slide valve 29 into its right hand position so that cylinder 26 is connected with the outlet 28. Piston 2 then moves toward the right, without encountering any resistance.

The upward movement of the column continues after spring 9 is fully expanded and produces a suction effect. Accordingly, check valve I0 is raised and liquid to be pumped is drawn through member 8 into casing and pipe 6.

This arrangement is primarily designed for cases where the fluid under pressure supplied to cylinder M is an elastic fluid, because, in this case, it is possible to admit fluid during only a small portion of the stroke and then to make use of its expansion.

I will now give, by way of example, numeric indications relative to the practical construction it an apparatus according to the present invenion.

In this example, it will be assumed that-it is desiredto pump water from a well having a depth not exceeding 50 metres.

In this case, the total length of the pipe may vary from 60 to 30 metres.

If no, additional masses such as those shown at M in Fig. 2, are used the period of oscillation of the system depends only upon the length of the pipe.

However, it should be noted that there are two periods to be considered for each depth, to wit:

(a) The natural period of the system when the apparatus is not supplying liquid, which will be hereinafter called non-working period, and,

(b) The period of the system when liquid is being pumped, which will be hereinafter called working period, the latter being higher than the non-working period, because it is equal to the sum of the latter and of the time of flow of the liquid that is pumped. I

For a pipe of a length of 60 ms., the pumping frequency corresponding to the state of resonance is 85 pump strokes per minute; for a length of the pipe of 30 ms., it is 120 pump strokes per minute.

Concerning the dimensions of the apparatus, the diameter of the upper portion of piston-like member 8, is '75 mms.; the stroke of this member is 87 mms.

Spring 9 is a coil spring having a diameter of 87 mms. It is made of a metal wire 12 mms. in diameter and wound into 15 revolutions. height of spring 9 is 180' mms., when compressed, and 26"! mms., When expanded.

The diameter of pipe 6 i 40 mms.

In these conditions, for a length of the pipe of 60 ms., the pumping frequency which corresponds to the resonance of the system is 79 strokes per minute. mensions above stated and an elevation of liquid of 50 ms., to a discharge of 875 litres per hour with a stroke of 30.6 cms, of the pump lever, the maximum velocity of water in the pipe being 1.80 rn. per second.

With the same apparatus, but with a length of the pipe of only 30 ms. and an elevation of The- It corresponds for the dims., the rhythm of pumping is 100 strokes per minute, producing a discharge of 1460 litres per hour, which corresponds to a stroke of the lever of an amplitude of 20.3 cms., the maximum velocity of water in the pump being 1.90 m. per second.

The figures above stated are the theoretical results given by calculations. If account is taken of pressure drops in the pipe, the following results can be expected: For a pipe length of 60-ms.,- the efficiency will be 54%; for a pipe length of ms., the efliciency will be 62%.

The eificiency increases when the output decreases.

Now, ifv the same apparatus is to be used for working between 30 ms. and 15 ms. of pipe length,

- while keeping the same range of frequencies, it

sufiices to ensure a supplementary pressure of 266 grs. per cm. for a stroke of 20 cms. of the pumplever. In the case of an apparatus having the characteristics above indicated, this supple mentary pressure being intended to overcome the pressuredrops of the liquid in the pipe under these conditions, the maximum velocity of the liquid in the pipe is 91 cms. per second.

Finally, concerning the pressures, it has been found that, at the bottom of the water column, if the length of the pipe is 60 ms. and with an elevation of 50 ms., the maximum pressure is equal to 17.5 kgrs. per cm. It is therefore possible practically to use weldless cold-drawn tubes of /49, as supplied on the market, which are tested'for at least 20 kgrs. per cmF.

For a length of the pipe of 30 ms. and an elevation of 25 ms., the pressure at the bottom of the column of liquid is only .12 kgrs. per cm?.

While I have, in the above description, disconduit, whereby said coulmncan oscillate in said conduit. motor means fOr imparting impulses to this column of liquid and pilot means responsive to the direction of flow of liquid through said conduit for controlling said motor so as to sustain the oscillation of liquid therein, a check valve at the lower end of said conduit for the inflow of liquid thereinto and discharge I means at the top of said conduit.

2. A pumping apparatus which comprises, in combination, a conduit adapted to contain a column of liquid, yielding suspension means for this column of liquid carried by the lower end of 7 said conduit, whereby said column can oscillate in said conduit, electric rriotor means for imparting impulses to this column of liquid, a circuit for said electric motor means, a switch in said circuit, means operative by the flow of liquid through said conduit for operating said switch in such manner as to control said electric motor means, so as to sustain the oscillations of liquid therein, a check valve at the lower end of said conduit for the inflow of liquid thereinto and discharge means at the top ofsaid conduit.

3. A pumping apparatus according to claim 2, in which said means operative by the flow of liq uid include two cylinders, pistons movable in said cylinders respectively and operatively connected with said switch so as to act thereon in opposite directions respectively and communication means interposed between said two last mentioned cylinders respectively and said conduit, said communication means opening in said conduit in directions opposed to each other.

4. A pumping apparatus which comprises, in

' combination, a conduit adapted to contain a column of liquid, yielding suspension means for this column of liquid carried by the lower end of said conduit, whereby. said column can oscillate in said conduit, a motor operated by a fluid under pressure for imparting impulses to this column of liquid, a slide valve for controlling said motor and a piston for operating said slide valve movable in a part of said conduit under the effect of the flow of liquid therein, for controlling said motor so as to sustain the oscillations of' liquid therein, a check valve at the lower end of said conduit for the inflow of liquid thereinto and discharge means at the top of said conduit.

5. A pumping apparatus according to claim 1 in which an adjustable mass is incorporated in the oscillating system to modify the period of oscillation thereof.

JEAN MERCIER.

closed what I deem to be practical and eflicient- 

